In recent years, at a medical site, there are growing needs for taking radiographs in a particular situation, such as taking radiographs of a patient in his or her room when it is difficult to move the patient out of the room, or taking radiographs urgently in an operating room. Therefore, a mobile X-ray apparatus is used widely which is movable to a patient's room or the like, for taking radiographs. Recently, another type of mobile X-ray apparatus is proceeding toward practical utilization, on which an image reader is installed for reading X-ray image information from the IP, in order that an X-ray image being taken is able to be checked immediately at the imaging site to determine on site whether or not re-radiographing is necessary.
By way of example, the patent document 1 discloses an X-ray apparatus used for round visits, which is equipped with an image information reader to read X-ray image information accumulated in the IP. This X-ray apparatus used for round visits transmits the X-ray image information read by the image information reader to a CRT display which is installed on the top of the apparatus.
In the meantime, the image reader conveys the IP in the vertical scanning direction, allowing laser light to perform scanning in the main scanning direction (being perpendicular to the vertical scanning direction), successively scans the overall IP and detects photo-stimulated luminescence at each point, thereby reading the X-ray image information. In order to obtain an accurate image, it is essential to conduct the IP conveyance and the laser scanning accurately with a high degree of precision, and the IP should not be subjected to vibration, shock, and skewing, while reading the X-ray image information.    [Patent document 1]    Japanese unexamined patent application publication No. 4-190224